Suction nozzle for a vacuum cleaner

ABSTRACT

A suction nozzle for a vacuum cleaner has a housing, a vacuum mouth disposed on the floor side in the housing, a cleaning roller mounted to rotate in the housing and driven by an electric motor, and a rechargeable battery unit for the energy supply of the electric motor. Via a rear connecting piece, the suction nozzle can be connected to a suction tube or a suction hose of a vacuum cleaner. The electric motor has a rated power of between 50 and watts, and the rechargeable battery unit has an energy density, relative to its total volume, of more than 200 watt-hours per liter (Wh/L).

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates to a suction nozzle for a vacuum cleaner, having a housing, a vacuum mouth disposed on the floor side in the housing, a cleaning roller mounted to rotate in the housing and driven by an electric motor, and a rechargeable battery unit for the energy supply of the electric motor. Via a rear connecting piece, the suction nozzle can be connected to a suction tube or a suction hose of a vacuum cleaner. Cleaning of a floor covering takes place particularly effectively, at the suction nozzle, because of a combination of the intake air flow passing through the suction nozzle and the movement of the cleaning roller. Since the suction nozzle is equipped with the rechargeable battery unit as an energy supply, connection to an external voltage source is not necessary during operation, and so the suction nozzle can be used and handled flexibly.

2. The Prior Art

Suction nozzles having the features described above are known from German Patent Nos. DE 3900577 A1 and DE 29802879 U1, and in various embodiments from practice. Because of the usual design criteria, these suction nozzles, which have a rechargeable battery unit as the energy supply, are equipped with relatively weak drive motors having an electric power of at most 30 watts, in contrast to suction nozzles that have a cleaning roller and are connected to an external voltage source. Decisive factors in the design of the suction nozzle include not only the costs for the electric motor and the rechargeable battery unit, but, in particular, the weight, reliability and overall volume of the suction nozzle. In this connection, the intake air flow contributes decisively to the cleaning effect of the known suction nozzles and is supported only to some extent by the cleaning roller. Thus, in the case of the known suction nozzles having a cleaning roller driven by a rechargeable battery, the air power at the suction nozzle is typically much greater than the electric power of the electric motor.

SUMMARY OF THE INVENTION

It is therefore an object of the invention to provide a suction nozzle that exhibits improved cleaning properties, and is easy to handle.

This object is achieved, according to the invention, in that the electric motor has a rated power of between 50 and 150 watts, and the rechargeable battery unit, relative to its total volume, has an energy density of more than 200 watt-hours per liter. The invention is based on the recognition that the synergy effects of the electrically driven cleaning roller, on the one hand, and of the intake air flow, on the other hand, are not optimally utilized in the known suction nozzles of the type in question. Because the rated power of the electric motor is at least 50 watts and preferably between 80 and 150 watts, very reliable and thorough cleaning of different textile floor coverings is possible. The cleaning roller is typically provided with helical brush strips, which are disposed around the circumference. As an additional or alternative example, however, lamellae made of an elastic material may also be provided. Because of the high electric power of the nozzle according to the invention, the depth of penetration of the cleaning elements of the roller brush can also be increased. Because of the high energy density of the rechargeable battery unit, in excess of 200 Wh/L, the improvement in cleaning ability is also accompanied by a compact structure and by good ease of handling of the suction nozzle.

Preferably, the energy capacity of the rechargeable battery unit is greater than 40 Wh (watt-hours), and particularly preferably, the energy capacity is between 50 Wh and 100 Wh. The suction nozzle according to the invention is suitable for cleaning almost all commercially available floor coverings, and effective cleaning can be achieved, in particular, on carpets and carpeted floors. Only extremely deep-pile carpets, whose fibers may become entangled in the cleaning roller, are not suitable for being cleaned with the suction nozzle according to the invention. The electric motor and the energy capacity of the rechargeable battery unit are preferably matched to one another, in such a way that an operating time of at least 30 minutes per rechargeable battery charge is assured, regardless of the type of floor covering to be cleaned with the suction nozzle. A sufficiently long operating time means that interruption for charging or replacing the rechargeable battery unit can be avoided during typical use of the suction nozzle in private homes. For the preferred use in private homes, an operating time of longer than one hour is not needed, in most cases, and so the maximum operating time achievable with one rechargeable battery charge should typically be between 30 minutes and one hour. Besides the total weight, which in the operative condition of the suction nozzle is preferably less than 2.5 kg and particularly preferably less than 1.5 kg, a uniform weight distribution is desirable from the viewpoint of easy handling. For example, the electric motor and the rechargeable battery unit may be disposed on opposite sides of the housing, in order to balance the suction nozzle.

The rechargeable battery unit may also be provided with differently shaped rechargeable batteries, which are disposed separately at locations spaced apart from one another. Particularly effective use of the available installation space, and particularly uniform weight distribution are possible by such a configuration of the rechargeable battery unit.

Within the scope of the invention, the rechargeable battery unit can be disposed in a fixed or movable manner, on or in the housing. For example, the rechargeable battery unit can be pushed into the housing or fastened to an external holder. In this regard, an exchangeable configuration permits simple replacement of a defective or discharged rechargeable battery unit by a charged replacement unit kept in readiness, and the operating time can also be prolonged without difficulty, if necessary. With an exchangeable configuration of the rechargeable battery unit, charging in an external charging station is possible. Even with an exchangeable configuration of the rechargeable battery unit, charging without separation from the suction nozzle can also be possible during an idle period. Depending on the configuration of the suction nozzle, the housing or the rechargeable battery unit is provided with a readily accessible charging connection. Finally, a holder that simultaneously functions as a charging station can also be provided for the suction nozzle, as an accessory.

The electric motor is typically coupled with the cleaning roller via a gear mechanism, such as a belt or a toothed-gear arrangement. In principle, however, a direct drive in a coaxial arrangement is also conceivable, in which case the electric motor is disposed at one end of the cleaning roller or integrated into the cleaning roller. Preferably, an electronic control for controlling the speed and/or torque of the electric motor is also provided. For example, the forces acting on the cleaning roller can depend very greatly on the surface to be cleaned, and increased friction can occur, for example, in the case of a deep-pile carpeted floor. Speed and/or torque control can take place in response to the instrumentally determined electric current intensity, the signals of sensors of the suction nozzle, and/or in response to manual inputs. For example, sensors that determine the floor composition or the degree of dirtiness can be provided on the underside of the housing of the suction nozzle. An array of switches could also be provided on the upper side of the housing, thus allowing a user to select various modes of operation.

In one embodiment, the rechargeable battery unit is based on a lithium-ion system. In this case, the rechargeable battery unit can be formed from at least one lithium-ion rechargeable battery, one lithium-polymer rechargeable battery, one lithium/manganese dioxide rechargeable battery, or one lithium/lithium cobalt oxide rechargeable battery. The cell structure of the lithium-polymer rechargeable batteries permits the manufacture of thin film batteries, and so lithium-polymer rechargeable batteries can be manufactured in almost any desired shapes, and, in particular, even in irregular shapes. Lithium-polymer rechargeable batteries can fill irregular interstices, and thus make optimal use of space. Lithium/manganese dioxide rechargeable batteries have particularly high operating safety, and so special protective circuits are not absolutely necessary. Furthermore, lithium/manganese dioxide rechargeable batteries can be manufactured inexpensively, and they do not contain any heavy metals, and thus can be handled with relatively few problems during disposal and in the event of defects.

In a preferred embodiment of the invention, in which the rechargeable battery unit is based on a lithium-ion system, the rechargeable battery unit can be provided with a rechargeable battery having an electrode whose surface is configured as a nanostructure, in which case the surface area is increased by a factor of 5, and preferably at least by a factor of 10, compared with a smooth surface. The maximum charging and discharge current is determined essentially by the surface area of the electrode. Because of the increase in surface area due to nanostructuring, very large charging and discharge currents can be achieved even with a rechargeable battery having a large capacity and a correspondingly large amount of electrochemically active material. Regarding a suction nozzle, for example, rapid charging can be achieved in a very short time interval of typically less than 10 minutes, and preferably less than 5 minutes. Furthermore, an elevated discharge current can also be drawn for a short time, for example to clean a very dirty floor section. With a rechargeable battery having a nanostructured electrode, this battery can be designed, for example, as a lithium-nanophosphate rechargeable battery.

For optimal use of space, the rechargeable battery unit may be provided with a rechargeable battery that has an outer contour different from tubular batteries. The outer contour is matched to the shape of the installation space present in the housing. In contrast to conventional tubular rechargeable batteries, the described configuration permits the rechargeable batteries to be disposed in otherwise unused interstices, whereby the use of volume is improved and the outside dimensions of the suction nozzle can be decreased. Furthermore, it is known from portable devices used in the field of entertainment electronics and equipped with lithium-ion rechargeable batteries, that the use of a replacement rechargeable battery that is not matched precisely to the charging electronics can cause destruction of the rechargeable battery and of the device itself. In extreme cases, the rechargeable battery may explode or catch fire. By virtue of an irregular, non-standardized geometry of the rechargeable battery unit and of the associated housing space, the use of unauthorized replacement rechargeable batteries can be largely precluded.

In addition to the described measures, the suction nozzle can also be optimized in terms of flow technology. For this purpose, continuous transitions can be provided along the flow path of the intake air, in order to reduce turbulence and friction. Furthermore, the vacuum power can also be increased by minimizing the proportion of leakage air, which enters not through the vacuum mouth but through gaps and crevices in the housing. For this purpose, it is possible, for example, to provide housing gaskets between parts of the housing, or sealing lips or sealing strips at articulated joints. A connecting piece at the rear side of the suction nozzle is typically connected to the housing via an articulated joint. To prevent leakage air from entering at this articulated joint, the intake air path inside the articulated joint can be bridged by inserting a flexible, airtight suction hose.

BRIEF DESCRIPTION OF THE DRAWINGS

Other objects and features of the present invention will become apparent from the following detailed description considered in connection with the accompanying drawings. It is to be understood, however, that the drawings are designed as an illustration only and not as a definition of the limits of the invention.

In the drawings, wherein similar reference characters denote similar elements throughout the several views:

FIG. 1 shows a suction nozzle according to the invention; and

FIG. 2 shows the suction nozzle parked in a charging station, and connected to a vacuum cleaner for floors.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring now in detail to the drawings, FIG. 1 shows a suction nozzle 1 according to the invention, for a vacuum cleaner 2, having a housing 3, a vacuum mouth 4 disposed on the floor side in the housing 3, a cleaning roller 6 mounted to rotate in the housing 3 and driven by an electric motor 5, and a rechargeable battery unit 8 comprising two rechargeable batteries 7 a, 7 b for the energy supply of electric motor 5. Electric motor 5 has a rated power of between 50 watts and 150 watts. The rechargeable battery unit formed from a large first rechargeable battery 7 a and a small second rechargeable battery 7 b has an energy density of more than 200 Wh/L (watt-hours per liter) relative to its total volume, and so it has an energy capacity of more than 40 watt-hours and preferably between 50 watt-hours and 100 watt-hours, despite its compact construction. With rechargeable battery unit 8, suction nozzle 1 can be operated for longer than 30 minutes on one rechargeable battery charge, regardless of the type of floor covering. Rechargeable batteries 7 a, 7 b are based on a lithium-ion system. Suitable examples are lithium-ion rechargeable batteries, lithium-polymer rechargeable batteries, lithium/manganese dioxide rechargeable batteries, lithium-nanophosphate rechargeable batteries, or lithium/lithium cobalt oxide rechargeable batteries.

Rechargeable batteries 7 a, 7 b of rechargeable battery unit 8 are inserted exchangeably into housing 3, from the rear, and first large rechargeable battery 7 a is disposed on one side of the housing and of electric motor 5, while the second smaller rechargeable battery 7 b as well as an electronic controller 9 are disposed on the other side of the housing. A uniform weight distribution is achieved by such a configuration. Furthermore, a total weight of less than 1.5 kg for suction nozzle 1 contributes to the ease of handling. Electronic control 9, which can also be connected to sensors of suction nozzle 1, is used to control the speed and torque of electric motor 5. Electric motor 5 is coupled to cleaning roller 6 via a toothed belt 10. Cleaning roller 6 is designed as a roller brush having brush strips 11 disposed helically around the circumference.

In order also to optimize the cleaning effect of the intake air, an optimally streamlined air path having continuous flow transitions is provided inside suction nozzle 1. Furthermore, to minimize the proportion of leakage air, a housing gasket 14 is provided between an upper part 12 and a lower part 13 of housing 3, while a flexible suction hose 16 is provided in the region of the tiltable connection between housing 3 and a suction-tube connection 15.

The exchangeable configuration of the rechargeable battery unit 8, comprising two rechargeable batteries 7 a, 7 b, makes it possible, in principle, to remove rechargeable batteries 7 a, 7 b for charging or, in particularly simple manner, even to replace them with corresponding replacement rechargeable batteries. Preferably, however, rechargeable battery unit 8 can be charged during an idle period, without being separated from suction nozzle 1. FIG. 2 shows suction nozzle 1 parked in a charging station 17 during an idle period, but still connected to a vacuum cleaner 2 via a suction tube 18. When vacuum cleaner 2 is not in use, suction nozzle 1 is stored in charging station 17, so that recharging and maintenance charging of the rechargeable battery unit 8 by means of charging electronics takes place in the charging station 17. By storing suction nozzle 1 in charging station 17, it is always possible to ensure a full charge, and, additionally, also a long service life of rechargeable battery unit 8.

Accordingly, while only a few embodiments of the present invention have been shown and described, it is obvious that many changes and modifications may be made thereunto without departing from the spirit and scope of the invention. 

1. A suction nozzle for a vacuum cleaner, comprising: a housing; a vacuum mouth disposed on a floor side in the housing; a cleaning roller mounted to rotate in the housing and driven by an electric motor; a rechargeable battery unit for supplying energy to the electric motor; and a rear connecting piece for connecting the housing to a suction tube or a suction hose of the vacuum cleaner, wherein the electric motor has a rated power of between 50 and 150 W (watts) and the rechargeable battery unit has an energy density, relative to its total volume, of more than 200 Wh/L (watt-hours per liter).
 2. The suction nozzle according to claim 1, wherein the rechargeable battery unit contains at least one battery selected from the group consisting of a lithium-ion rechargeable battery, a lithium-polymer rechargeable battery, a lithium/manganese dioxide rechargeable battery, a lithium-nanophosphate rechargeable battery, and a lithium/lithium cobalt oxide rechargeable battery.
 3. The suction nozzle according to claim 2, wherein the rechargeable battery unit is provided with at least one rechargeable battery that has a non-tubular outer contour and that is matched to a shape of an installation space present in the housing.
 4. The suction nozzle according to claim 3, wherein the rechargeable battery unit has rechargeable batteries which are shaped differently from each other and which are disposed separately at locations spaced apart from one another.
 5. The suction nozzle according to claim 1, wherein the energy capacity of the rechargeable battery unit and the rated power of the electric motor are matched to one another, in such a manner that operating time on one rechargeable battery charge is longer than 30 minutes, regardless of the type of floor covering. 